The installer and updater scripts should force $wgShowExceptionDetails and other debug options on to assist in debugging of maintenance tasks.
The options to hide details from error reporting are there to reduce the risk of information exposure to the general web (path disclosure, private keys in backtrace parameters, etc), but it should be safe to expose this to the system administrator and will help in diagnosing problems such as the report shown in bug 9980.
Version: 1.11.x
Severity: enhancement